The subject invention is directed toward the art of pipe joints and couplings and more particularly, to a joint construction or assembly particularly suited for corrugated plastic pipe or tubing.
The invention is particularly suited for connecting large diameter corrugated plastic drain pipe or tubing and will be described with particular reference thereto; however, it will be apparent to those skilled in the art that the joint structure could be incorporated in many other sizes of corrugated pipe or tubing used for a variety of purposes in many different environments.
Corrugated plastic pipe or tubing is widely used for many types of agriculture and industrial drainage systems. The pipe is made up in a variety of diameters and lengths which are joined together by many different types of joints and connections. In the smaller sizes various types of connections are provided which rely upon the inherent resiliency of the plastic to permit interconnection of adjacent pipe lengths. Connections which rely upon such inherent resiliency are not particularly suited to large diameter pipe sizes in that the force required to move the pipe joints into locking relationship can be substantial. Additionally, the large size pipes must be made up in shorter lengths necessitating a large number of joints for a given length.
In some instances, it has been proposed to provide a separate connecting element to encircle the adjoining ends of the pipe. However, the addition of a separate element can substantially increase the cost of the piping system. Moreover, time and labor involved in installing the separate elements can become substantial when a substantial length comprised of many interconnected pipe sections is required.
In some instances, it has also been proposed to provide a joint structure in which the mating components of the joint can be integrally formed on the end portions of the pipe lengths or sections and which joint is easy to assemble with a minimum of force being required. Such an arrangement is shown in the commonly assigned U.S. Pat. No. 3,929,359, the teachings of which are incorporated herein by reference. While the structure shown in U.S. Pat. No. 3,929,359 has provided satisfactory and advantageous results, it does have limitations for certain uses and installations. Particularly, the arrangement of this prior patent does not provide means for positively locking two adjacent lengths of the pipe or tubing together at the joint area.
The present invention contemplates a new and improved structure which provides a new joint construction which is a simple, economical, may be included as an integral part of the ends of plastic pipe or tubing lengths, which facilitates adjacent lengths of pipe to be positively locked together at the joint area and which permits adjacent lengths of pipes to be bent at sharp angles to each other at the joint areas without disturbing the integrity of the joint.